1. business and industrial
2. manufacturing

MEDICAL DEVICE ENCLOSURES
SMI is the world-leading thermoformer of
highly-aesthetic, complex medical device enclosures
and products
Situation
A large, medical device manufacturer was producing covers for their treatment
system in a variety of different materials and manufacturing processes. The
gantry covers were composed of fiberglass panels, while the accompanying
stand was a combination of fiberglass, reaction injection molded (RIM), and
thermoformed components. This combination presented not only issues with
supplier management but also generated fit and alignment difficulty due to
assembly of parts from three different processes and manufacturers. These
issues all lead to extensive assembly time, aesthetic issues, and increased
manufacturing costs.
In an effort to improve aesthetics, reduce cost, increase production output, and
minimize installation time, a decision was made to move production out of
fiberglass and into all plastic through a single manufacturing process. The
customer’s initial assessment identified RIM as the preferred process. Their
team anticipated that by using the RIM process, they would be able to mold in
numerous attachment features to accept screws and realize better overall tolerance and ease of assembly.
SMI’s Deisgn Philosophy
SMI strives to maintain the highest quality standards as well as aesthetic appeal
while also taking into consideration the importance of designing for
functionality. Our process allows for undercuts and snap-fit features to be
formed into the part which reduces the number of bosses required for physical
attachment during assembly. This in turn reduces assembly time and fit issues,
lowering the total cost of manufacturing. Traditional thermoforming design
philosophy dictates that back-side attachment features are essential to securely
hold a component in place. This approach attempts to maintain straight
alignment in “panel to panel” mating surfaces and securely hold the component
to the chassis. However, the numerous attachment points add cost in design
time, tooling, manufacturing and assembly.
©Copyright Providien, LLC. All rights reserved. Specialty Manufacturing, Inc. is a division of Providien, LLC
www.providienmedical.com/ www.smi-mfg.com
Specialty Manufacturing, Inc
6740 Nancy Ridge Dr
San Diego, CA 92121
Phone 800.491.1652
Fax 858.450.0400
www.smi-mfg.com
Program Challenges
Prove to he customer that
thermoforming was
cost-neutral to RIM
Demonstrate uniqueness of
SMI’s design philosophy as it
pertains to quality, aesthetics,
and speed of assembly
Eliminate need for numerous
attachment features requiring
screws and other hardware
SMI Design Philosophy (con’t)
SMI’s extensive experience in the development of undercut design has taken
new innovative steps in using undercuts to structurally mate and align panel to
panel surfaces. This innovative design philosophy has eliminated the need for
bosses on the back side of a part. These same perimeter undercuts are used to
mount the panel to chassis.
When properly designed, undercuts provide the part with structural integrity
and rigidity. The keys to successfully implementing SMI’s undercut philosophy
are (1) the ability to design tooling that can generate the necessary precision
and (2) forming equipment capable of producing 85 PSI in air pressure to the
back side of the part during the forming process. The result is repeatability, tight
tolerance, and visual excellence.
Not All Thermoformers Are Created Equal
SMI’s design philosophy impressed the customer. A cost analysis indicated SMI’s
proposal was cost neutral when compared with the RIM process.
Thermoforming was now considered a viable option. As a result, three
additional thermoforming companies were given the opportunity to bid on the
project. After researching the various options, the customer concluded SMI’s
approach to manufacturing and design was superior compared to the other
thermoformers and to the other manufacturing processes as well.
Design Assistance
Once SMI was awarded the business, the work to redesign the system for a
single process commenced. SMI’s engineering team was involved from the
beginning. The customer was directed to design each part in accordance with
their size and shape requirements. SMI took on the task of working closely with
the customer to take the initial designs and add in all of the attachment features
in order to incorporate snap-fits and undercuts that would simplify final
assembly. Through a series of collaborations, SMI worked with the customer to
create these attachment features without altering the appearance of the parts
in any way.
SMI recognizes that our innovative design approach is unique in the
thermoforming process. SMI is therefore committed to providing engineering
support and design assistance to help guide customers to incorporate features
that will allow for higher functionality, reduced assembly time and cost, and
improved aesthetic appearance
©Copyright Providien, LLC. All rights reserved. Specialty Manufacturing, Inc is a division of Providien, LLC
www.providienmedical.com/ www.smi-mfg.com
Outcome
SMI provided the
customer with quality
and consistency
75% reduction in on-site
cover assembly time
Improved aesthetic
appearance
Garnered numerous US
and international design
awards